Most people shade the truth every day: 11 lies per week is the average. (Admit it, traffic was fine--you're late because extra sleep was finer.) But lying's not just bad for your karma. A study from Notre Dame found it can give you headaches and sore throats. It might be due to the stress of managing your fibs, says lying expert Robert Feldman, Ph.D., dean of the College of Social and Behavioral Sciences at the University of Massachusetts, Amherst. But there's no need to be totally frank: You just have to cut out three little lies every week to boost wellness.